Reagents for the determination of cerebral regional acetylcholinesterase activity

摘要

The present invention relates to N-alkylpiperidine derivatives represented by general formula (1) or (2); chemistry chemdraw filechemistry mol file;wherein R¹ represents optionally fluorinated lower alkyl; R² represents lower alkyl; and R³ represents alkenyl substituted at the 1-position with hydroxy, lower alkoxy, lower alkoxyalkyloxy, lower alkoxyalkyloxyalkyloxy, or lower alkanoyloxy and substituted at the end with radioactive iodine, or alkenyloxymethyl substituted at the end with a radioactive iodine reagent containing the same for assaying central local AchE activity; a method for assaying the central local AchE activity; and labeled precursors of the above compounds. After easily passing through the blood-brain barrier, these compounds are hydrolyzed specifically by AchE in the brain into alcohols, which are then captured by the brain. In contrast, alcohols formed outside the brain do not migrate into the brain. The compounds of the invention emit &ggr;-rays at an appropriate energy level. These characteristics make the compounds highly useful as tracers for SPECT in assaying the central AchE activity.